TAICHUNG, Taiwan (BRAIN)—Retailers will have an extra gear to sell on Shimano-equipped road bikes as soon as next summer as a cable-shifted 11-speed Dura-Ace group appears destined for the company's 2013 product line. Before long the extra cog will inevitably appear on the Dura-Ace Di2 electronic-shifting group and the lower-priced Ultegra group, most industry insiders here at Taichung Bike Week agree.
On the sales floor, the move closes Shimano's cog-gap to Campagnolo and is sure to generate some upsells, but what Shimano's first post-decimal drivetrain will mean for parts inventory and sales is less certain. It all comes down to exactly how the Japanese giant executes the addition, and there are only a few hints available.
The news leaks.
Two weeks ago Shimano gave its OEMs the first semi-technical documents on the 11-speed group; there are images of its part list floating around on the web (See the BRAIN Facebook page for some links and a discussion. facebook.com/BicycleRetailer).
Shimano officials have told BRAIN previously that the company purposefully puts varying (mis?)information on such documents to help identify leakers. If that's true it means the details on the document should be taken with a grain of salt. Or perhaps the claim was to discourage premature publication of the details. Either way, it’s an impressive level of corporate craftiness to contemplate.
The known knowns:
In any case, the documents indicate that the 2013 group will be available late summer, perhaps on complete bikes as soon as August.
The 11-speed Dura-Ace hub spec retains 130mm OLD spacing. Some engineering types had hoped the company would push 11-speed out to 135mm to make space for more gears and disc rotors, while some retailers will likely be relieved that a change to road frame rear spacing has been kicked down the road a few seasons.
Ten-speed cassettes will fit on Shimano 11-speed hubs with a spacer. The 11-speed cassettes are about 2mm wider than 10-speed cassettes, but they could fit some 10-speed wheels.
It appears that 11-speed levers will shift "accurately" across 10-speed cassettes with one redundant click. For dealers this means they can inventory "new" Shimano 11-speed wheels that will be backward-compatible for 10-speed customers.
The known unknowns:
Shimano documents indicate that 11-speed and 10-speed chains will not be compatible. The specification is somewhat of a moot point, however, since Shimano always says a specific chain is needed for each of its drivetrains, while tinkerers have found that's not always the case. The fact that Shimano has widened the cassette (instead of simply narrowing the spacing) indicates that the chain may not be much, if any, narrower than a 10-speed chain.
It's not clear if a 10-speed crank will work with an 11-speed drivetrain, but if the chain is the same width, it should.
Will Shimano 11-speed be compatible with Campy's 11-speed groups? The chatter here is that the two drivetrains will at least be close enough to allow the same wheels to be used for neutral race support.
(By the way, there is also chatter that the 2014 XTR offroad group will go electric and offer 11 cogs.)
It may not be as bad as it could have been: Keeping to the 130 OLD means some wheels will be cross-compatible and a new road frame spacing standard is avoided. The ability to use an 11-speed shifter on a 10-speed cassette is also a nice touch.
Whether dealers will need to stock 11-speed Shimano chainrings—along with the 9-speed and 10-speed rings they have already—is uncertain. Obviously they will need to stock the new 11-speed cassettes and shifters, and likely the derailleurs. As mentioned previously, some 10-speed wheels will work with the new cassettes, and 11-speed wheels can be used with 10-speed cassettes with a spacer.